You will need to log into the Attendee Service Center.
Once logged in, you will click on the CE and Certificate tab.
You will then scroll down on the page to the daily tabs. Click on the day you are missing the sessions or use the search field to find the missing session(s). Click on "Add CE" under each session that is missing. This will add the session(s) to your record of participation.
You can also remove CE. Click on "Remove CE" under the each session. This will remove the session from your record of participation.